Silver Bow County Area and Parts of Beaverhead and Jefferson Counties, Montana
The dominant drainage class is Well drained and the dominant hydrologic group is A (high infiltration, low runoff). This report summarizes the major soil map units across the survey area to help you understand what to expect when buying, building, or gardening in Silver Bow County Area and Parts of Beaverhead and Jefferson Counties, Montana.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Stecum-Rock outcrop-Comad complex, 35 to 70 percent slopes | 5K | Somewhat excessively drained | A | Very limited | Very limited |
| Stecum-Rock outcrop-Basincreek complex, 25 to 50 percent slopes | 5K | Somewhat excessively drained | A | Very limited | Very limited |
| Dumps, mine | 4K | Not rated | Not rated | ||
| Stecum, very bouldery-Rock outcrop-Zonite, very bouldery complex, 20 to 50 percent slopes | 4K | Somewhat excessively drained | D | Very limited | Very limited |
| Valleyflat sandy loam, 1 to 4 percent slopes | 4K | Well drained | A | Not limited | Very limited |
| Valleyflat complex, 0 to 2 percent slopes | 4K | Well drained | A | Not limited | Very limited |
| Minestope, extremely bouldery-Branham, extremely bouldery-Rock outcrop complex, 8 to 35 percent slopes | 4K | Somewhat excessively drained | D | Very limited | Very limited |
| Beeftrail-Dinnen-Rock outcrop complex, 4 to 15 percent slopes | 3K | Somewhat excessively drained | B | Very limited | Very limited |
| Beeftrail-Dinnen-Highrye complex, 8 to 45 percent slopes | 3K | Well drained | B | Very limited | Very limited |
| Philipsburg-Monaberg complex, 2 to 8 percent slopes | 3K | Well drained | C | Not limited | Somewhat limited |
| Monaberg loam, 1 to 4 percent slopes | 3K | Moderately well drained | C | Somewhat limited | Very limited |
| Sebud-Bearmouth complex, 1 to 4 percent slopes, very stony | 3K | Well drained | B | Somewhat limited | Very limited |
| Maurice-Sigbird-Surdal complex, 20 to 50 percent slopes, stony | 3K | Well drained | B | Very limited | Very limited |
| Rubick, rubbly-Rubble land complex, 40 to 75 percent slopes | 3K | Somewhat excessively drained | A | Very limited | Very limited |
| Basincreek-Peeler-Stecum complex, 15 to 45 percent slopes | 3K | Well drained | A | Very limited | Very limited |
| Maurice-Surdal-Mawspring complex, 12 to 35 percent slopes, stony | 3K | Well drained | B | Very limited | Very limited |
| Highrye-Beeftrail-Oro Fino complex, 1 to 8 percent slopes | 3K | Well drained | B | Not limited | Very limited |
| Sebud-Sieben complex, 8 to 30 percent slopes, stony | 3K | Well drained | B | Very limited | Very limited |
| Illiano, very stony-Euell, very stony-Rock outcrop complex, 8 to 30 percent slopes | 3K | Well drained | D | Very limited | Very limited |
| Evaro-Eastridge-Vitroff complex, 20 to 50 percent slopes | 3K | Somewhat excessively drained | A | Very limited | Very limited |
What This Means
Building & Foundations
About 64% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes. A geotechnical assessment is recommended before building.
Septic Systems
About 88% of soils are rated "very limited" for septic absorption fields. Despite good drainage overall, limitations may stem from shallow bedrock, steep slopes, or seasonal conditions. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.
Gardening & Agriculture
Well-drained soils on sloped terrain — good for most plants but watch for erosion. Terracing, contour planting, and mulching help retain moisture and topsoil. Drip irrigation is more effective than sprinklers on slopes.